Question

Найдите производную функции f(x) = cos log2x.

Answer 1

$\displaystyle f(x)=cos(log_2x)\\\\f'(x)=-sin(log_2x)*(log_2x)'=-sin(log_2x)*\frac{1}{x*ln2}=-\frac{sin(log_2x)}{x*ln2}$